The Pfizer vaccine study published in the New England Journal of Medicine highlights its efficacy, showing a 95% effectiveness rate with a lower confidence interval of 90%. The analysis indicates that younger subjects experienced more frequent side effects, and the importance of receiving both doses is emphasized, as effectiveness after the first dose ranges from 30% to 68%. Discussions suggest that the observed protection begins approximately two weeks after the first dose, raising questions about the necessity of the second dose. The FDA's analysis relies on comprehensive data beyond published studies, and the potential for future research on a one-dose regimen is noted. Overall, the conversation underscores the complexities of vaccine efficacy and the regulatory processes involved.